Manufacturer in Japan cooperating with investigators looking into overheating, fire on Boeing 787s

Japanese and U.S. investigators began a probe Monday into the maker of the lithium-ion batteries used in Boeing’s grounded 787 jets.

Tsutomu Nishijima, a spokesman for GS Yuasa, the battery manufacturer, said investigators visited the company’s headquarters in Kyoto, Japan, and that Yuasa was cooperating with the probe.

All 50 of the 787 Dreamliners that Boeing has delivered to airlines were grounded after an overheated battery forced the emergency landing of an All Nippon Airways 787 flight last week in western Japan.

GS Yuasa’s batteries are the focal point of the investigation into the causes of a fire on a Japan Airlines plane and ANA’s emergency landing. Chicago-based Boeing said last week it won’t deliver more 787s until the Federal Aviation Administration confirms the safety of the Dreamliner’s flammable lithium-ion batteries that are part of the electrical system supplied by Thales.

The Japan Airlines plane that caught fire in Boston on Jan. 7 didn’t exceed its intended voltage, according to the U.S. National Transportation Safety Board. Information released Sunday by the agency suggests the fire that precipitated a grounding of Boeing’s newest jet wasn’t caused by overcharging. Investigators said they were expanding their probe to look at the battery’s charger and the jet’s auxiliary power unit.

The 787 is Boeing’s most technologically advanced plane, featuring a body made of composite materials instead of the traditional aluminum. It conserves fuel by using five times more electricity to power its systems than other planes, and is Boeing’s first model to rely on lithium-ion batteries.

All four plants where GS Yuasa builds lithium-ion batteries are in Japan. The batteries supplied to the Dreamliners are made at a factory in its Kyoto headquarters. The electrical system, which the battery is embedded into, is manufactured by French company Thales, Europe’s biggest defense-electronics maker.

Boeing chose lithium-ion batteries for the 787 because they hold more energy and can be quickly recharged. Boeing got regulators’ permission to use lithium batteries in the jetliner in 2007, three years after U.S. passenger planes were barred from carrying non-rechargeable types as cargo because of their flammability.

A unit of GS Yuasa won a contract in August to supply lithium-ion battery cells to the International Space Station. Boeing oversees all contract work at the space station as NASA’s prime contractor.

Monday’s investigation at GS Yuasa involved an introductory meeting and factory tour, with deeper studies into product quality and other issues to follow as the probe continues, said Tatsuyuki Shimazu, the chief air worthiness engineer at Japan’s Civil Aviation Bureau’s Aviation Safety Department.

Two investigators from the FAA and an investigator from Japan’s government were conducting the probe into how the batteries are made and assembled and into any quality issues, he said.

“We are in the midst of collecting information, so as to whether there is a problem or not has not yet been determined,” Shimazu said.

The company, which employs nearly 12,300 staff, expects revenue of $3.2 billion for the year ending in March — with only around 1 percent of that coming from its aircraft battery business. The company’s batteries are used primarily in motorbikes, industrial equipment and power supply devices.

GS Yuasa, in which automaker Toyota Motor has a 2.7 percent stake, reported an operating profit of around $160 million in the year to last March.

The burned insides of the ANA battery showed it received voltage in excess of its design limits. However, a battery that caught fire in a Japan Airlines Boeing 787 in Boston earlier this month was found not to have been overcharged.

U.S. government investigators said there could still be problems with wiring or other charging components.

Investigators also are being sent to the U.K. to probe a valve actuator maker for the 787, Japan’s transport ministry said, without identifying the target company.

In the U.S., investigators from the National Transportation Safety Board planned to meet today with officials from Securaplane Technologies, manufacturer of the charger for the 787s lithium-ion batteries, at the company’s headquarters in Tucson, said Kelly Nantel, a spokeswoman for the board.

Japan is the biggest market to date for the Dreamliner, with JAL and ANA flying 24 of the 50 passenger jets that Boeing has delivered.